Sooo... I tried my Rumble 40 Studio and my Rumble 1×15 cab with a 100 W head and see how low they go before they bottom out and no longer play the fundamental. I used
Szynalski's Online Tone Generator to play a pure sine wave through the speakers.
And here's what I found.
The Studio plays A1 (55 Hz), but it struggles a bit. It can
almost play E1 (~41 Hz) at a significantly increased volume but it doesn't make any sense to do it live.
The 15" cab can play A1 effortlessly, but the ports are tuned somewhere between E1 and A1, so at E1, there's port chugging, which obviously gets worse at B0 (~31 Hz). Now, if you plug the ports, it plays E1 effortlessly and you can hear B0 with some distortion.
I figure with 30 Hz port tuning, it could play B0 perfectly, but I didn't do calculations for cab volume whether it will still be large enough after making the ports longer.
Bummer.
So here's what I'm wondering: Does the 2×10" cab have lower frequency response than the 1×15"? Which Rumble goes the lowest? Does any of them actually play B0 at a reasonable level in the mix? It almost feels like chasing the ultimate LF extension of those cabs makes no sense if a small 10" dedicated subwoofer in my home setup easily plays back 40 Hz and with EQ, it handles down to 35 Hz.
Alternatively, I could play back with the ports plugged, but then there's loss of ventilation and the speaker is no longer as effectively cooled which may be a problem at 100 watts.
Any advice?